Toward a Generalized Model of Fish Migration

Recent research utilizing mathematical approaches to marine fish migration problems is critically reviewed. An analogy between the diffusion of organisms and physical quantities is drawn, and the well-known heat diffusion equation is examined as a possible general model for migration. Specific solutions to this equation under various boundary conditions utilizing empirically determined movement parameters derived from tagging and recapture data are obtained utilizing digital computer techniques. Available data are examined with a view toward suggesting the relative significance of the coefficients of directed movement and dispersion under various conditions. The possible mechanisms involved are briefly considered and the utility of the model in testing various hypotheses regarding the precision of the orientation is demonstrated.